Medicines have various formulations in accordance with their use, and as to oral medicines 16 kinds of formulations are described in the Pharmacopoeia of Japan, 9 of which are liquid formulations and the remaining 7 of which are solid formulations.
Although the liquid formulations among the oral medicines have the advantage of easy oral administration, their use is extremely limited because of the following reasons: medicines which are easily decomposed by moisture and humidity in the air cannot be applied to the liquid formulations; it is impossible to manufacture the liquid formulations considering drug delivery system (DDS) such as enteric formulations and sustained release dosage formulations; and off-tastes and off-flavors of the liquid formulations can be masked with great difficulty.
On the other hand, of 7 kinds of the solid formulations, there are basically 5 kinds which are swallowed in the solid state, namely, powder, granule, pills, tablets and capsules. Since these solid formulations in particular granule, tablets and capsules can overcome the disadvantages described in the case of the liquid formulations by varying design for the formulations, these formulations are widely utilized, recently.
Each of these solid formulations is usually swallowed with cold or hot water, but it is not always easy even for a healthy person to swallow a solid formulation smoothly. Powder or granule, for example, often adheres to the throat, and consequently the person feels an off-taste such as a bitter taste or sometimes coughs. The person also experiences difficulty in swallowing pills, tablets or capsules due to the degree of their size, the smoothness of their surface or the absorbability of water.
It is much more difficult for such persons as a child, a feeble person, a sickly person and an old person than for a healthy person to swallow these solid formulations. Even if these persons try with water, they often fail to swallow smoothly by coughing due to the high flowability of water, or swallow only water and leave the solid formulation in the mouth.
When a person cannot swallow the solid formulation in a usual way, the formulation may be administered by crushing it. However, if tablets are crushed, the masked off-tastes and off-flavors will be released in the mouth. Furthermore, in the case of the crushed enteric coated tablets or prolonged release dosage forms, the formulation not only cannot function but also can cause side-effects.
The primary users of medicines are not healthy persons but those, as mentioned above, who feel difficulty in swallowing the solid formulation. Considering a tendency to remarkable increase in population of aged persons, the problem of difficulty in administering the solid formulation cannot be ignored simply as a special case, but should be treated as a universal problem. That is to say, the community will request the research and development of the solid formulations wherein not only the functions such as the effects of medicines but also the easiness of the administration is pursued.
The present inventors have already proposed an easily administrable medicine comprising a seamless capsule enclosing effective ingredients and at least one of a gel and a high viscous liquid (Japanese Patent Laid-Open No. 5-139958). This invention has been quite useful in providing an easily administrable medicine having a novel orally administrable formulation for such a person as a child, a feeble person, a sickly person or an old person.
However, the seamless capsule used in this easily administrable medicine sometimes breaks when the seamless capsule is mixed with a gel or a high viscous liquid, while this mixture is stored, or when the mixture is administered, and leaks the enclosed effective ingredients, which leads to a problem: the person feels an off-taste such as a bitter taste.
Then, the present inventors have repeated studies in order to obtain the conditions whereunder the seamless capsule does not break which is used as a medicine having an orally administrable formulation, and consequently have accomplished the present invention.
It is an object of the present invention to provide a food-like medicine which can be easily swallowed by such a person as a child, a feeble person, a sickly person or an old person, and furthermore which can be safely administered without the possibility of leaking the effective ingredients.